The present invention relates to rotary motors, and, more particularly, to rotary hydraulic motors which drive a cantilevered shaft.
Rotary auger shredders, such as the auger shredder disclosed in Koenig U.S. Pat. No. 4,253,615, include a housing which is divided into a grinding chamber and a motor cabinet. A rear wall separating the grinding chamber and cabinet supports a bearing on which is mounted a radial piston hydraulic motor and an auger screw which is cantilevered into the grinding chamber. The hydraulic motor includes a stationary part and a rotating part which is bolted to a mounting plate or disc which supports the screw.
The stationary motor part is connected to a hydraulic pump which supplies pressurized hydraulic fluid to drive the motor. The stationary part is connected to the housing framework within the cabinet by a single torque arm which extends radially from the rotational axis of the motor. The torque arm is attached to the housing by a link which is pivotally connected at one end to a clevis mounted on the housing, and at its other end to a clevis formed in the end of the link arm.
A problem with such a design is that torque forces transmitted to the link arm through the motor are unbalanced and create unwanted reactive radial loads, which may shorten the life of the motor and bearing. Further, the link connection between the torque arm and frame lacks means for absorbing shocks which may be created during reversal of the motor and auger screw rotation, or which occur when the auger encounters a relatively hard object such as a block of metal or hardened concrete. Accordingly, there is a need for an auger shredder having a motor and torque arm assembly which minimizes bending moments applied to the hydraulic motor and bearing, and which is capable of absorbing shocks encountered by the auger shredder during operation, and is balanced to minimize the radial reactive load occurring within the motor and bearing.